Members of the order Anaeroplasmatales can appear as different shapes at different times in their lifecycles. Cells which are 16–18 hours old tend to be
spherical. When the cells are older, they can take on various shapes. Anaeroplasmatales are not motile. Anaeroplasmatales
cannot grow in the presence of oxygen. They do grow at a temperature of 37 °C on microbiological media, where they form irregular-shaped colonies with a "fried-egg" appearance, similar to other
mycoplasmas. Anaeroplasmatales are
negative by
Gram stain. ==History==